title: Vitamin D supplement doses and serum 25-hydroxyvitamin D in the range associated with cancer prevention.
abstract: BACKGROUND
  Studies indicate that intake of vitamin D in the range from 1,100 to 4,000 IU/d and a serum 25-hydroxyvitamin D concentration [25(OH)D] from 60-80 ng/ml may be needed to reduce cancer risk. Few community-based studies allow estimation of the dose-response relationship between oral intake of vitamin D and corresponding serum 25(OH)D in the range above 1,000 IU/d.
  
  
  METHODS
  A descriptive study of serum 25(OH)D concentration and self-reported vitamin D intake in a community-based cohort (n = 3,667, mean age 51.3 ± 13.4 y).
  
  
  RESULTS
  Serum 25(OH)D rose as a function of self-reported vitamin D supplement ingestion in a curvilinear fashion, with no intakes of 10,000 IU/d or lower producing 25(OH)D values above the lower-bound of the zone of potential toxicity (200 ng/ml). Unsupplemented all-source input was estimated at 3,300 IU/d. The supplemental dose ensuring that 97.5% of this population achieved a serum 25(OH)D of at least 40 ng/ml was 9,600 IU/d.
  
  
  CONCLUSIONS
  Universal intake of up to 40,000 IU vitamin D per day is unlikely to result in vitamin D toxicity.
authors.affiliation: University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors.forename: Cedric F
authors.initials: CF
authors.lastname: Garland
authors.forename: Christine B
authors.initials: CB
authors.lastname: French
authors.forename: Leo L
authors.initials: LL
authors.lastname: Baggerly
authors.forename: Robert P
authors.initials: RP
authors.lastname: Heaney
mesh_terms: D015331:Cohort Studies; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000517:prevention & control*; D057566:Self Report; D014807:Vitamin D / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D